Ionic liquids as environmentally friendly catalysts were applied in biodiesel production.In this paper,the advances in the ionic liquids catalysts,namely B acidic ionic liquids with sulfonic acid groups or acidic anion groups,L acidic ionic liquids and new B basic ionic liquids,and their application in biodiesel production were reviewed.The synthesis and the characterization of the ionic liquids were summarized.The catalytic reaction mechanism of the ionic liquids in the biodiesel production was discussed.I...